Two improvements in Brauer's theorem on forms
Abstract
Let be a Brauer field, that is, a field over which every diagonal form in sufficiently many variables has a nonzero solution; for instance, could be an imaginary quadratic number field. Brauer proved that if are homogeneous polynomials on a -vector space of degrees , then the variety defined by the 's has a non-trivial -point, provided that is sufficiently large compared to the 's and . We offer two improvements to this theorem, assuming is infinite. First, we show that the Zariski closure of the set of -points has codimension , where is a constant depending only on the 's and . And second, we show that if the strength of the 's is sufficiently large in terms of the 's and , then is actually Zariski dense in . The proofs rely on recent work of Ananyan and Hochster on high strength polynomials.
Keywords
Cite
@article{arxiv.2401.02067,
title = {Two improvements in Brauer's theorem on forms},
author = {Arthur Bik and Jan Draisma and Andrew Snowden},
journal= {arXiv preprint arXiv:2401.02067},
year = {2024}
}
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22 pages